Wood products such as utility poles for electric and telephone transmission wires, piling supports for highway and railroad bridges, pier timbers, and wood building structural components are all subject to attack by wood-destroying fungi and insects.
One method of combating such destruction is by the internal application of fumigants including chemical agents which are toxic to the wood destroying organisms. Unfortunately, most effective chemical agents are usually not only toxic to destructive organisms, but also to human beings, animals and the environment. For example, the toxic chemical treatment agents are particularly hazardous to the wood-treating personnel who must handle the fumigants. As a result, wood-treating personnel must wear cumbersome and unreliable face shielding and goggles or, in some instances, full face respirators when applying the toxic chemicals to the wood products. Additionally, environmental contamination may occur if the toxic fumigants seep or spill into the environment.
There are several known methods and devices used to internally treat wood products with fumigants. Fumigants containing chemical agents are often liquid and applied by pouring the fumigants into pre-drilled bores and then plugging the bores to prevent the fumigants from escaping therefrom. For example, U.S. Pat. No. 4,989,366, describes an external cylinder containing toxic chemicals which flow into a pre-drilled bore by first piercing a seal.
This device may expose the personnel handling the fumigants to toxic vapors and environmentally damaging chemicals may spill onto the ground. Additionally, seasoning check and knots in the treated wood product may cause leakage of fumigants into the environment.
Other methods of treating wood include peeling off a seal of a chemical-containing capsule to allow chemical vapors to slowly escape from the capsule. The unsealed capsule is then dropped into a pre-drilled bore in the wood product to be treated and the bore is plugged with a wooden peg to seal in the vapors. Using this method, the working personnel again are exposed to toxic vapors when the capsule is dropped into the pre-drilled opening and vapors may leak around and through the wood peg.
Therefore, there is a need for a wood-treating system for safe and effective treatment of wood products without environmentally damaging spillage and dangerous exposure of toxic chemical agents to the personnel handling the wood-treating device.